Rheumatoid factor - autoantibodies that react as autoantigens with their own immunoglobulins G, which underwent changes under the influence of any agent (for example, a virus ).
Synthesized by plasma cells of the synovial membrane . From the joints they enter the bloodstream, where they create immune complexes that damage the walls of blood vessels and the synovial membrane. Reference values: up to 30 IU / ml.
The following factors can cause an increase in rheumatoid factor:
- Rheumatoid arthritis (patients with a seropositive form of rheumatoid arthritis are prone to a more severe course of the disease: high inflammatory activity, difficulty in achieving remission , severity of the destructive process, extraarticular manifestations);
- Other diffuse diseases of the connective tissue ( systemic lupus erythematosus , systemic scleroderma , sarcoidosis , dermatomyositis , Sjogren's syndrome , etc.);
- Infectious diseases - septic endocarditis , infectious mononucleosis , tuberculosis , leprosy , viral hepatitis in the active phase;
- Parasitic diseases - malaria , leishmaniasis , trypanosomiasis ;
- Waldenstrom macroglobulinemia , chronic lymphocytic leukemia , malignant neoplasms , especially metastases in the synovial membrane, after DLT and PCT6).